A close contact of someone with bird flu became ill on the same day, the C.D.C. reported. But the second person was not tested, and the cause of the illness is unknown.

A Utah research laboratory may play a key role in advancing bird flu testing amid an outbreak in commercial and backyard poultry flocks.

The Centers for Disease Control and Prevention has picked five lab partners to develop a test for avian influenza A(H5N1) — bird flu — including ARUP Laboratories in Salt Lake City. The other lab partners are Quest Diagnostics,